ASTM C418-2005 Standard Test Method for Abrasion Resistance of Concrete by Sandblasting《用喷砂法测定混凝土抗磨性的标准试验方法》.pdf

1、Designation: C 418 05Standard Test Method forAbrasion Resistance of Concrete by Sandblasting1This standard is issued under the fixed designation C 418; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu

2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers determination of the abrasionre

3、sistance characteristics of concrete by subjecting it to theimpingement of air-driven silica sand. It is intended for use asa basis for the development of informed judgment.1.2 The values stated in SI units are to be regarded as thestandard. Inch-pound units are shown for information purposesin pare

4、ntheses.1.3 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.NOTE 1Users of thi

5、s test method are advised that there are knownsafety hazards associated with the use of silica as a blasting media.Consult the silica manufactures MSDS to insure that the latest recom-mended health and safety practices are being followed.NOTE 2Other procedures are available for measuring abrasion re

6、sis-tance of concrete surfaces in addition to subjecting it to air driven silicasand. Consideration should be given to other methods of testing asoutlined in ASTM C 779/C 779M, ASTM C 944, and ASTM C 1138. Thetest method most closely representing service conditions should be used.1.4 The text of thi

7、s standard references notes and footnoteswhich are provided as explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered as requirements of this standard.2. Referenced Documents2.1 ASTM Standards:2C 127 Test Method for Density, Relative Density (Sp

8、ecificGravity), and Absorption of Coarse AggregateC 778 Specification for Standard SandC 779/C 779M Test Method for Abrasion Resistance ofHorizontal Concrete SurfacesC 944 Test Method for Abrasion Resistance of Concrete orMortar Surfaces by the Rotating-Cutter MethodC 1138 Test Method for Abrasion R

9、esistance of Concrete(Underwater Method)3. Significance and Use3.1 This test method covers the laboratory evaluation of therelative resistance of concrete surfaces to abrasion. Thisprocedure simulates the action of waterborne abrasives andabrasives under traffic on concrete surfaces. It performs acu

10、tting action that tends to abrade more severely the lessresistant components of the concrete.4. Apparatus4.1 ScalesThe scale shall have a capacity of 5000 g ormore. The permissible variation at a load of 5000 g (11 lb) shallbe 6 0.5 g (0.2 oz).4.2 WeightsThe permissible variations on weights used in

11、weighing shall be as prescribed in Table 1. The permissiblevariations on new weights shall be one half of the values givenin Table 1.4.3 Sand Blast ApparatusThe sand blast apparatus shallconsist of an injector-type gun. The gun shall have a high-velocity air jet fed by a suitably controlled rate of

12、flow for theabrasive material. The nozzle shown in Fig. 1 shall consist ofcold-rolled bar stock, 40 mm (1.5 in.) long, or hardened toolsteel HRC 48 6 2 as determined by Test Methods E 18, drilledto 6.40 6 0.02 mm (0.250 6 0.001 in.) approximately 700 kPa(100 psi) through the center. The walls of the

13、 nozzle shall havea 45 bevel on the inside at the upper end. A compressed airsupply of approximately 100 psi (690 kPa) shall be availableand equipped with a pressure-control device. Provision shall bemade to collect the spent abrasive and dust. Suitable jigs andclamps shall be provided to hold the t

14、est specimen in a fixedposition with relation to the discharge end of the nozzle. Forlaboratory wear testing of concrete specimens a commercialsand blast cabinet may be selected similar to that shown in Fig.2.1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete A

15、ggregates and is the direct responsibility of SubcommitteeC09.62 on Abrasion Testing of Concrete.Current edition approved Feb. 1, 2005. Published February 2005. Originallyapproved in 1958. Last previous edition approved in 1998 as C 418 98.2For referenced ASTM standards, visit the ASTM website, www.

16、astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.4 Sh

17、ieldThe shield shall be square or circular, 150 mm(6 in.) on a side or diameter, made from zinc-coated steel sheetor equivalent, having a thickness in the range of 0.90 to 1.90mm (0.035 to 0.075 in.). The shield shall have an opening28.70 6 0.25 mm (1.13 6 0.01 in.) in diameter in the center(See Not

18、e 3).NOTE 3An opening of 28.7 mm (1.13 in.) is equivalent to 6.45 cm2(1in.2). The purpose of the opening in the shield is to limit the abraded areato approximately 1 in.24.5 AbrasiveThe abrasive shall conform to SpecificationC 778 for 2030 sand (predominantly graded to pass an850-m (No. 20) sieve an

19、d be retained on a 600-m (No. 30)sieve).5. Preparation of Specimens5.1 Immerse the specimens in water for 24 h and thensurface dry with a damp cloth to obtain a saturated, surface-drycondition at the time of test.6. Calibration of Apparatus6.1 Adjust the air pressure to 410 6 1 kPa (59.5 6 1 psi)and

20、 collect the abrasive for a period of 1 min. Adjust the rateof flow of abrasive to 600 6 25 g/min (See Note 4).NOTE 4Aball valve between the abrasive supply and the gun inlet hasbeen found satisfactory for adjusting the flow of abrasive.6.2 The abrasive shall be regraded or replaced after every 60mi

21、n of operating time in order to maintain a uniform grading.6.3 Acold-rolled steel nozzle shall be replaced every 60 minof operating time. A hardened tool steel nozzle shall bechanged as required to maintain the original uniform flow andoriginal blast pattern.7. Procedure7.1 Place the specimen with t

22、he surface to be tested normalto the nozzle axis and at a distance of 75 6 2.5 mm (3.0 6 0.1in.) from the end. Clamp the specimen, with shield attached,firmly in place. Expose the surface to the blast for a period of1 min. Repeat this on at least eight different spots on thesurface. Determine the ab

23、raded volume by filling the abrasioncavities with an oil base modeling clay. Press the clay into thecavities manually with a moderate amount of finger pressureand level flush with a straight edge. Determine the mass of theclay supply before and after the cavities are filled to thetolerance listed in

24、 Table 1 instead of removing the clay fromthe filled cavities. Repeat filling with clay at least once on eachspecimen to ensure reproducible results.8. Calculation8.1 Calculate the mass of clay, Wc, as follows:Wc5 Wi2 Wfwhere:Wi= mass, initial supply, andWf= mass, final supply.8.2 Calculate the spec

25、ific gravity of clay, D, as follows:D 5 B / B 2 C!where:B = mass of clay in air, g, andC = mass of clay in water, g.NOTE 5Appendix X1 of Test Method C 127 provides guidance on thedevelopment of the equations used in the calculation of specific gravity(relative density to water) using the mass of cla

26、y in air and the mass ofclay when suspended in water.8.3 Calculate the volume of clay, V, per cavity in cubiccentimetres, as follows:V 5 W / Dwhere:W = mass of clay in cavity, andD = specific gravity of clay.8.4 Calculate the abrasion coefficient loss on a volumetricbasis, expressed in cubic centime

27、tres per square centimetre, inorder to compensate for variable densities of specimens, asfollows:TABLE 1 Permissible Variations on WeightsWeight, gPermissible Variations onWeights in Use, g1000 60.50500 60.35300 60.30250 60.25200 60.20NOTEAll dimensions are approximate except where tolerances aresho

28、wn. Inch-pound dimensions shown here for clarity purposes only.FIG. 1 Gun Nozzle AssemblyC418052Ac5 V / Awhere:Ac= abrasion coefficient, cubic centimetres per squarecentimetre, andA = area of surface abraded, square centimetres.9. Report9.1 Report the following information:9.2 Report the abrasion co

29、efficient loss to the nearest 0.01cm3/cm2.9.3 Report the location of the concrete where the specimenwas obtained and other characteristics of the concrete, ifknown.10. Precision and Bias10.1 On a limited sampling (Note 6), the single-operatorcoefficient of variation has been found to be 9.1 %.3There

30、fore,results of two properly conducted tests by the same operator onthe same material using the same equipment should not differby more than 25.8 %3of their average.10.2 On a limited sampling (Note 6), the multi-operatorcoefficient of variation has been found to be 10.3 %.3There-fore, results of two

31、 properly conducted tests by two operatorson the same material using the same equipment should notdiffer from each other by more than 29.1 %3of their average.NOTE 6The data, on file at ASTM Headquarters, involve two opera-tors performing the tests on samples made from the same batch andrepeated on a

32、nother day. Two concrete mixtures having different expectedabrasion resistance were also used. The tests were conducted in onelaboratory using the same equipment. As more laboratories become moreequipped and capable of performing the test, a more detailed interlabora-tory test program will be conduc

33、ted.10.3 Since there is no acceptable reference material suitablefor determining bias for the procedure in this test method, nostatement of bias is being made.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this stand

34、ard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be review

35、ed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible

36、 technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Cons

37、hohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).3These numbers represent, respectively, the (1s %) and (d2s %) limits asdescribed in Practice C 670 for Preparing Precision and Bias Statements for TestMethods for Construction Materials.FIG. 2 Sand Blast CabinetC418053